Air compressor

ABSTRACT

An air compressor and engine comprising a plurality of independent cylindrical compression chambers, each of said compression chambers having an inlet valve, an exhaust valve and a piston connected by rods to a crank-shaft, said plurality of chambers in two sets, the first set of chambers being greater in number than the second set of chambers, whereby the apparatus serves as an air compressor in which said first set of chambers are adapted for the primary compression chambers for feeding the compressed air to said second set of chambers provided for further compression of the air, or as an air compressor and engine in which said first set of chambers are adapted for the engine by means of suitable switching means, while said second set of chambers for an air compressor, or as an engine in which said first and second sets of chambers are adapted for the engine by means of said switching means.

United States Fatetit [1 Elena AIR COMPRESSOR Takahiro Ueno, 5-11, 4-Bancho, Wakayama, Japan Filed: Sept. 22, 1971 Appl. No; 182,613

Related US. Application Data Continuation-in-part of Ser. No. 873,881, Nov. 4, 1969.

Inventor:

[30] Foreign Application Priority Data [56} References Cited UNITED STATES PATENTS 4/1954 Ochel et a1. 417/237 1,847,260 3/1932 Pardee 3,426,523 2/1969 Staub 417/237 X FOREIGN PATENTS OR APPLICATIONS 587,743 1/1925 France 417/265 n11 3,744,934 1 Judy is, W735 Primary Examiner-Carlton R. Croyle Assistant ExaminerRichard E. Gluck AttorneyDawson, Tilton, Fallon & Luzmus [57] ABSTRACT An air compressor and engine comprising a plurality of independent cylindrical compression chambers, each of said compression chambers having an inlet valve, an exhaust valve and a piston connected by rods to a crank-shaft, said plurality of chambers in two sets, the first set of chambers being greater in number than the second set of chambers, whereby the apparatus serves as an air compressor in which said first set of chambers are adapted for the primary compression chambers for feeding the compressed air to said second set of chambers provided for further compression of the air, or as an air compressor and engine in which said first set of chambers are adapted for the engine by means of suitable switching means, while said second set of chambers for an air compressor, or as an engine in which said first and second sets of chambers are adapted for the engine by means of said switching means.

1 Claim, 14 Drawing Figures Patented July I0, 1973 5 Sheets-Sheet r Patented July 10, 1973 5 Sheets-Sheet 5 Patented July 10, 1973 5 Sheets-Sheet l FIG/0 Patented July 10, 1973 3,744,934

5 Sheets-Sheet 'o P FIG/.1

am coMPRnsson RELATED APPLICATION This application is a continuation-in-part of copending application Ser. No. 873,881 filed Nov. 4, 1969.

The present invention relates to an air compressor.

A principal object of the present invention is to provide an air compressor and engine in one which serves as an air compressor whereby highly compressed air is effectively obtained with small power source, or as an air compressor which may be partially used as an engine, or serves wholly as an engine. More particularly, an object of the present invention is to provide an air compressor and engine in one which is provided, within one body, with a plurality of compression chambers each having a compression piston therein, the compression pistons being so arranged by a crank-shaft as to be successively driven with slightly varied compression timing, said plurality of compression chambers being devided into two sets so that the air compressed in the one set of the compression chambers is sent to the other set of the compression chambers to be further compressed, or the one set of the compression chambers serves for the engine while the air is compressed in the other set of the compression chambers, or all of the compression chambers serve for the power engine.

Further, another object of the present invention is to provide a compression chamber which has suitable switching means whereby the mixed gas in case of an engine or the air in case of an air compressor is taken in through an inlet duct, and the exhaust air in case of an engine is exhausted through an exhaust duct or the compressed air in case of an air compressor is led into a tank.

Further, another object of the present invention is to provide a valve switching device, which is included in said switching means, adapted to change the switching timing of inlet and exhaust valv'es provided in each compression chamber so as to meet the different timing of each valve in case of an engine and an air compressor, respectively.

Furthermore, another object of the present invention is to provide an air compressor which has, in each compression chamber, a residual air exhaust duct with a force valve opening at the same time with the closure of the exhaust valve, to extract the hot compressed residual air remaining in the cylinder clearance of each compression chamber, whereby the inlet inertia force is increased by opening an inlet valve at an earlier timing. Consequently, high inlet and outlet efficiencies areobtained, and in addition, the rapid increase of the temperature in the compression chamber is prevented.

The other objects and advantages of the present invention will become apparent from the following detailed description and accompanying drawings, in which:

FIG. 1 is a diagrammatic plan view of an air compressor of the present invention;

FIG. 2 is a view in vertical section of the same;

FIG. 3 is a schematic view showing a compression chamber in the air compressor of the present invention;

FIG. 4 is a schematic view showing the flow of the inhaled air in the air compressor of the present invention;

FIG. 5, FIG. 6 and FIG. 7 are the partial elevations of a cam-shaft in the air compressor of the present invention;

FIG. 8 and FIG. 9 are the diagrammatic front views of two inclined cams facing each other;

FIG. it) is a diagrammatic plan view showing another modified air compressor in accordance with the present invention;

FIG. I1 is a diagrammatic sectional view showing a compression chamber in the air compressor illustrated in FIG. Ill;

FIG. 12 is a vertical sectional view of the modified compression chamber of the present invention;

FIG. 13 is a valve timing diagram of the compression chamber in the air compressor shown in FIG. 3 and FIG. Ill; and

FIG. 14 is a P.V. diagram of the compression chamber in the air compressor shown in FIG. 3 and FIG. ill.

Now, referring to FIGS. 1 and 2, there is shown an embodiment of an air compressor and engine in accordance with the present invention. A. plurality of compression chambers in vertical cylinder form, namely six compression cylinders IA, 18, MI, ID, IE and IF illustrated, are formed within one body 3 in parallel. The compression chambers are respectively provided with each of the pistons 2A, 2B, 2C, 2D, 2E and 2F for compressing the air or the mixed gas which has been inhaled into the compression chambers.

Further, as illustrated in FIG. 3, in the upper portion of each of the compression chambers are provided an inlet port 5 having an inlet valve 4 which is operated by the force of a cam and an exhaust port '7 having an exhaust valve 6 also operated by the force of a cam. In operative relationship with the movement of pistons, said inlet and exhaust valves are adapted to perform the following movement. In case that each of said compression chambers is adapted for an air compressor, the inlet valve 4- is opened and the exhaust valve 6 is closed to inhale the air into the chamber when each of the pistons moves down from the top dead center, namely in the suction stroke. When the piston moves upward from the bottom dead center, namely in the compression stroke, both of the valves 4 and 6 are closed, and when the predetermined compression is achieved, the exhaust valve 6 is opened to get the compressed air in the chamber exhausted into each exhaust duct.

Further, in case that each of said compression chambers is adapted for a 4 cycle engine, the suction valve 4 is opened and the exhaust valve 6 is closed to inhale the mixed gas into the chamber when each of the pistons moves down from the top dead center, namely in the suction stroke. Then, when the piston moves upward from the bottom dead center, namely in the compression stroke, both of the valves 4 and 6 are closed and when the highest compression is achieved, namely at the top dead center, the mixed gas is tired to push the piston downwardly to the bottom center, namely the expansion stroke, through which the valves 4 and 6 are closed. Then, when the piston moves upwardly from the bottom dead center, namely in the exhaust stroke, the exhaust valve 6 is opened to get the exhaust gas out of each chamber through the exhaust port 7 into each exhaust duct.

As commonly known in a 4 cycle engine or the like, the valve actuating mechanism of the present invention comprises of a crank-shaft which makes one rotation during one reciprocating movement of each piston in each compression chamber to cause half rotation of a cam-shaft, a cam mounted to said camshatt which causes vertical movements of a tappet connected to each valve by each rod, whereby each valve is switched in accordance with the movement of each piston.

That is, as shown in FIG. 1 and FIG. 2, to the crankshaft are connected the pistons 2A, 2B, 2C, 2D, 2E and 2F by each rod 11. The cam-shafts l7 and 18 are so arranged as to perform half rotation during one rotation of the crank-shaft, namely a reciprocal movement of the pistons, by means of sprockets 8 and 9 mounted on said crank-shaft 10, sprockets 12 and 13 mounted respectively on the cam-shafts l7 and 18, and chains 14 and 15. Said cam shaft 17 is provided with eight pairs of inclined cams 16X and 16Y as shown in FIG. 8 and FIG. 9, the surfaces of smaller circumference of said cams in each pair facing each other with equal spaces, whereby eight valves provided in the compression chambers 1A, 1B, 1C and 1D are switched to meet each adaptation of the chambers. Also, said cam-shaft 18 is provided with four pairs of the same inclined cams as those on the cam-shaft 17, whereby four valves provided in the compression chambers 1E and IF are switched to meet each adaptation of the chambers.

As shown in FIG. 5, FIG. 6 and FIG. 7,.said each pair of the inclined cams are so arranged that the one thereof is in contact with the tappet 19, and by sliding the cam-shaft the suitable cam for the air compressor or the engine is brought into contact with the tappet l9. Said tappet 19 is connected to each valve by each rod, so that when the tappet is raised by said cam, the valve connected to this tappet is opened.

That is, the inclined cam 16Y is for the air compressor while the inclined cam 16X for the four cycle engine. Therefore, as in FIG. 5, when the cam-shafts 17 and 18 are in the position to bring the cam 16Y into contact with the tappet 19, all compression chambers are adapted for the air compressor. When the inclined cams 16X of the cam-shaft l7 and 16Y of the camshaft 18 are in contact with the tappet 19 as in FIG. 6, that is, the cam-shaft 17 is slided to the direction of arrow A in FIG. 5, the compression chambers 1A, 1B, 1C and 1D are used for the four cycle engine while the compression chambers 1E and IF for the air compressor. When the inclined cams 16X of both cam-shafts 17 and 18 are in contact with the tappet 19, that is, the cam-shafts 17 and 18 are slided to the direction of arrow A in FIG. 5, all compression chambers are used for the four cycle engine. In other words, as above described, each valve is switched easily to meet the adaptation of each compression chamber by sliding the cam-shafts l7 and 18.

Referring to FIG. 4, the air flow into and out of the compression chambers is to be explained. In. case that all compression chambers 1A, 1B, 1C, 1D, 1E and IF are adapted for the air compressor, the air taken in from an air inlet 21 is led through a common duct 22,

a switch valve device 33, a common duct 23 and manifolds 23A, 23B, 23C and 23D. to the compression chambers 1A, 1B, 1C and 1D. Said switch valve device puts the lid on one of the three ducts connecting one another at said valve device to let the other two ducts communicate each other. In this case, therefore, the ducts 22 and 23 are opened to each other while a duct 32 for mixed gas being closed. Another switch valve device 34 is also provided to stop the air from flowing to ducts 236 and 30.

Upon being compressed in the compression chambers 1A, 1B, 1C and 1D, the air is led out of respective exhaust ports 7 through respective manifolds 24A,

24B, 24C and 24D into common ducts 24 and 24G, passing through a switch valve device 35 which makes communicated the ducts 24 and 246 in this case. From the duct 24G further through a duct 25 and then manifolds 25E and 25F, passing through a switch valve device 36 which makes communicated the ducts 24G and 25 in this case, the air is sent into the compression chambers 1E and IF to be further compressed. The highly compressed air is then led into a tank T through manifolds 26E and 26F and ducts 26 and 27T, passing through a switch valve device 37 which makes the ducts 26 and 27T communicated in this case. Since the air is thus compressed in two steps, highly compressed air is obtained with a relatively small power source. In the above described case in which all compression chambers are adapted for the air compressor, each piston is actuated by the rotation of the crank-shaft 10 connected by a clutch 38 to a motor M, a power source.

Secondly, in case that the compression chambers 1A, 1B, 1C and ID are adapted for the engine whereby rotating the crank shaft 10 so as to actuate the other compression chambers 1E and IF as an air compressor, the mixed gas from a carburetor C is led through a duct 32, the switch valve device 33, the common duct 23 and manifolds 23A, 23B, 23C and 23D to the compression chambers 1A, 1B, 1C and 1D, said switch valve device making the ducts 32 and 23 communicated in this case. In the compression chambers 1A, 1B, 1C and 1D, the mixed gas is burned to the exhaust gas, which is led out of respective exhaust ports 7 through respective manifolds 24A, 24B, 24C and 24D into the common duct 24 communicated in this case to a duct 248 by the switch valve device 35. The exhaust gas, thus, is led through the duct 248 to an outlet 31 to be exhausted therefrom. On the other hand, the air inhaled from an inlet 29 is led through ducts 30, 23G, 25 and manifolds 25E and 25F to the compression chambers 1E and IF. In this case, said ducts 30 and 230 are communicated by the switch valve device 34 while said ducts 23G and 25 by the switch valve device 36. Upon being compressed in the compression chambers 1E and IF, the air is sent into the tank T through the same route with that in the first case.

In the above described case, the compression chambers 1A, 1B, 1C and 1D serve as a power engine to rotate the crank-shaft 10 whereby actuating the compression chambers 1E and IF as the air compressor so that the clutch 38 is cut off.

Thirdly, in case that all compression chambers are adapted for the engine, the mixed gas from the carburetor C is led through the same route with that in the second case as regards the compression chambers 1A, 1B, 1C and 1D, to the outlet 31 to be exhausted therefrom, while concerning the compression chambers 1E and IF, the mixed gas is led through the duct 23G, 25 and manifolds 25E and 25F to the chambers 1E and IF, said ducts 23 and 23G being communicated by the switch valve device 34 and said ducts 23G and 25 by the switch valve device 36. In the compression chambers 1E and IF, the mixed gas is burned to the exhaust gas, which is led out of respective exhaust ports 7 through respective manifolds 26E and 26F into common duct 26 communicated in this case to a duct 278 by the switch valve device 37. Thus, through the duct 278 the exhaust gas is led to the outlet 28 to be exhausted therefrom.

As theretofore described, the air compressor and engine of the present invention is constructed to change its adaptations quite readily.

Referring to FIGS. llll and ill, a modified air compressor of the present invention is shown. In this embodiment, three compression chambers 39 are formed in a body ill, each of the compression chambers being formed in approximately circular shape in cross section with approximately triangular eccentric rotor disposed therein. The eccentric rotor 41 is kept in contact with the inner circumferential surface of the compression chamber 39 at respective vertexes 42A, 42B and 42C on the peripheral surface thereof and is adapted for rotation by means of a shaft Ml to be driven by a power source M through a gear 43. The compression chamber is so formed in section that when the rotor lil is driven in the direction indicated by the arrow in the figure, the spaces a and b formed between vertexes 42A and 423 or between 42A and 42C are reduced as they approach the exhaust ports and 35. The air inhaled through the inlet ports 46 and as, accordingly, is compressed as the spaces a and b are reduced by the rotation of the rotor 41. Upon the spaces a and b being communicated with the exhaust ports 45 and 45, the air is taken out from the exhaust ports.

Just as in the foregoing embodiment, the compressing operations performed respectively in the aforementioned three compression chambers 39 in this embodiment are so adapted that each of the operations may take place with different timing. That is, the mechanism is such that, when one revolution of the shaft is effected, a series of compression operations in the three compression chambers is completed, so that, as seen in the foregoing embodiment, the shaft can be brought into smooth rotation without being vibrated. It will be observed in the FIG. 10 that according to this embodiment, the primary compression is first carried out in compression chambers 39A and 39B. The compressed air thereafter taken out from the chamber is led, as indicated by the arrow, into a secondary compression chamber 39C through ducts 47A, @718 and 47C to be further compressed, whereupon it is sent into a tank T through an exhaust duct 4-8.

it will be easily understood that, by providing said modified air compressor with a suitable switching device, said compressor may be served for an engine just as the foregoing embodiment. The detailed description, therefore, is not given here.

Referring to FIG. 12, there is shown a piston air compressor provided with three force valves, a residual air exhaust valve Sll, an inlet valve 51 and an exhaust valve 52. Said residual air exhaust valve 50 is so adapted as to be simultaneously opened with the closure of the exhaust valve 52 whereby the hot compressed residual air remaining in the cylinder clearance (the volumetric difference between cylinder and piston stroke) is exhausted into the air. Accordingly, the opening time of the inlet valve 51 is hastened as shown in the valve timing diagram (FIG. 13), wherein A0 is the opening time of the inlet valve in the conventional air compressor while A, is that of the inlet valve in the air compressor of the present invention having the residual air exhaust valve 5'6. The opening time of the inlet valve 51 being thus hastened by the residual air exhaust valve Ed, the inlet inertia force of the air in an inlet duct 53 is increased whereby inlet and outlet efficiencies are also increased, while the rapid rise of the temperature in a compression chamber 53 is moderated by exhausting the hot residual air.

in the HG. 113 and HG. l4, 0 indicates the time when the piston is at the top dead center, while L at the bottom dead center. The opening time of the inlet valve in the conventional compressor is indicated by A0, closing time thereof by B, opening time of the exhaust valve by Co and closing time thereof by I). On the other hand, the opening time of the inlet valve in the air compressor having the residual air exhaust valve 5% of the present invention is indicated by All, closing time thereof by B, the opening time of the exhaust valve by Cil, the closing time thereof and opening time of the residual air exhaust valve Sill by D, and the closing time thereof by E. Further, Pa indicates the pressure in the inlet pipe 53,

Pb: predetermined outlet pressure,

Vb: the cylinder volume with the piston at the top dead center, namely cylinder clearance volume,

Va: the cylinder volume with the piston at the bottom center,

Vao: the cylinder volume at the opening time of the inlet valve in the conventional air compressor, namely Ao,

Vol: the cylinder volume at the opening time of the exhaust valve in the same, namely Co,

Vco: the cylinder volume at the opening time of the inlet valve in the compressor having the residual air exhaust valve 5% of the present invention, namely All, and Vcll: the cylinder volume at the opening time of the exhaust valve in the same, namely Cl.

As illustrated in FIG. lid, the hot pressed air remaining in the cylinder clearance being exhausted by the re sidual air exhaust valve Sill of the present invention, the pressure is rapidly reduced compared with the conventional air compressor whereby the inlet time All becomes earlier than the conventional Ao. in consequence, the actual inlet stroke volume (Vb-Vol) of the air compressor of the present invention becomes greater than that of the conventional air compressor, namely (Vb-Vac). Accordingly, the inlet inertia efficiencyof the air in the inlet duct is increased whereby the inlet and outlet efficiencies are increased as well.

In other words, per one cycle, the outler volume (Vc-Va) of the air compressed under the predetermined pressure of the present invention, namely P becomes greater than that of the conventional air compressor (Vco-Va). Therefore, such an air compressor with high outlet efficiency that moderates the rapid rise of the temperature in the compression chambers is obtained.

I claim:

1. A combination air compressor and engine apparatus comprising a body having a plurality of cylindrical bores, the bores providing first and second sets of compression chambers, each of the sets having a plurality of compression chambers and the first set having more compression chambers than the second set, each of the compression chambers being provided with an inlet and an outlet opening, an inlet valve and an outlet valve mounted in the body for each compression chamber for opening and closing the inlet and outlet openings, a piston reciprocably mounted within each compression chamber, crank shaft means rotatably mounted in the body and connected to the pistons for reciprocating the pistons, .21 first cam shaft axially adjustable and rotatably mounted on the body and associated with the first set of compression chambers and a second cam shaft axially adjustable and rotatably mounted on the body and associated with the second set of compression chambers, each of the cam shafts being operatively connected to the crank shaft to be rotated thereby, a pair of dams for each inlet valve and each outlet valve for each compression chamber of the first set mounted on the first cam shaft and a pair of cams for each inlet valve and each outlet valve for each compression chamber of the second set mounted on the second cam shaft, each pair of cams comprising spaced-apart engine and compressor cams, each engine and compressor cam of each pair having an inclined cam face facing the other cam of the pair and adapted to engage tappet means, and tappet means reciprocably mounted on the engine for each inlet and each outlet valve for opening and closing the valves, each cam shaft being independently axially adjustable between a first position in which the engine cams of each pair of cams on the cam shaft engage the tappet means and a second position in which the compressor cams of each pair of cams on the cam shaft engage the tappet means, the cam surface of each of the engine cams adapted to reciprocate the tappet means once during each revolution of the associated cam shaft and the cam surface of each of the compressor cams adapted to reciprocate the tappet means twice during each revolution of the associated cam shaft whereby the apparatus may be operated as an engine by moving each cam shaft into the first position and as a compressor by moving each cam shaft into the second position and as a combination engine and compressor by moving the first cam shaft into the first position and the second cam shaft into the second position. 

1. A combination air compressor and engine apparatus comprising a body having a plurality of cylindrical bores, the bores providing first and second sets of compression chambers, each of the sets having a plurality of compression chambers and the first set having more compression chambers than the second set, each of the compression chambers being provided with an inlet and an outlet opening, an inlet valve and an outlet valve mounted in the body for each compression chamber for opening and closing the inlet and outlet openings, a piston reciprocably mounted within each compression chamber, crank shaft means rotatably mounted in the body and connected to the pistons for reciprocating the pistons, a first cam shaft axially adjustable and rotatably mounted on the body and associated with the first set of compression chambers and a second cam shaft axially adjustable and rotatably mounted on the body and associated with the second set of compression chambers, each of the cam shafts being operatively connected to the crank shaft to be rotated thereby, a pair of cams for each inlet valve and each outlet valve for each compression chamber of the first set mounted on the first cam shaft and a pair of cams for each inlet valve and each outlet valve for each compression chamber of the second set mounted on the second cam shaft, each pair of cams comprising spaced-apart engine and compressor cams, each engine and compressor cam of each pair having an inclined cam face facing the other cam of the pair and adapted to engage tappet means, and tappet means reciprocably mounted on the engine for each inlet and each outlet valve for opening and closing the valves, each cam shaft being independently axially adjustable between a first position in which the engine cams of each pair of cams on the cam shaft engage the tappet means and a second position in which the compressor cams of each pair of cams on the cam shaft engage the tappet means, the cam surface of each of the engine cams adapted to reciprocate the tappet means once during each revolution of the associated cam shaft and the cam surface of each of the compressor cams adapted to reciprocate the tappet means twice during each revolution of the associated cam shaft whereby the apparatus may be operated as an engine by moving each cam shaft into the first position and as a compressor by moving each cam shaft into the second position and as a combination engine and compressor by moving the first cam shaft into the first position and the second cam shaft into the second position. 